What do I do if my F3 button doesnt work on minecraft?
Solution 1:
It sounds like your F3 key may be broken on your keyboard. You can check by opening Internet Explorer or Chrome (browsers) and press F3, it should open the "search this page" box along the top. Same as if you pressed CTRL +F. I don't know any mac keyboard mappings.
Here is a post that describes how to remap your keys for either Windows or Mac.